It is known to detect a presence of a trailer being towed by a host-vehicle. Typical trailer-detection systems may require an operator of the host-vehicle to input a dimension of the trailer, or require the operator to position the trailer such that the trailer-detection system may be calibrated. Other trailer-detection systems rely on the connection of a special wire harness from the trailer to the host-vehicle to indicate a presence of a trailer, or require the operator to manually activate a tow-switch.